Fifa has given Liverpool permission to sign Argentinian midfielder Javier Mascherano from West Ham.

The deal with the Anfield club, understood to be a loan, was initially in doubt because Mascherano had already played for two clubs competitively this season - the Hammers and Brazilian club Corinthians. However, he has failed to make an impact at Upton Park, after joining the Londoners on the final day of the summer transfer window along with compatriot Carlos Tevez.

"I hope he will be with us tomorrow," said Liverpool boss Rafael Benítez after last night's 2-1 win over the Hammers. And a statement from Fifa this morning confirmed that it would let Mascherano move to Anfield - if he so wishes.

"After due consideration of all aspects, the Fifa single judge ruled that 'upon registration for Liverpool FC during the present registration period, the player Javier Mascherano is eligible to play in official matches with the said club with immediate effect'," it read.

The ruling appears to take into account the fact that the Brazilian and English seasons do not run parallel, with the Campeonato Brasileiro beginning in April and ending in December - thus cutting through the close season in this country. "Particular emphasis was given to the safeguard of the sporting integrity and the crucial element of overlapping sports seasons between associations, notably in cases in which a sports season starts prior and ends beyond July 1," continued the statement.

"Yet, the single judge made it clear that such permission can only be granted under very restrictive preconditions, such as they exist in the case at stake, yet never occurred in a case that was submitted to the attention of the competent deciding bodies at an earlier stage. In particular, he emphasised that a series of elements related, on the one hand, to the duration and the positioning of the relevant sports seasons as well as to the respect of the registration periods and, on the other hand, to the duration and respect of the employment contracts concerned, need to be cumulatively met."